Disposable stapler

Abstract

A stapler having a pistol grip which can be entirely formed as a one-piece molding, without need for separate springs, connectors or other parts. The main springs are not stressed until the trigger is pulled for the first time. Staples of a special configuration are closed by a driver having a specially shaped forming end.

Having described the invention, what is claimed is: 
     
       1. In a stapler having a staple guide passage wherein staples are sequentially engaged by a driver and are formed against an anvil, a supply of staples positioned to be fed into said passage for engagement by said driver,   a feed spring biasing said supply toward said passage, and   a supplementary spring movable into engagement with said feed spring to supply additional force thereto when said driver is moved to engage a staple from said supply.   
     
     
       2. The stapler of claim 1 wherein said supplementary spring moves with said driver. 
     
     
       3. The stapler of claim 2 wherein said supplementary spring is a cantilever leaf spring projecting from and generally parallel to said driver. 
     
     
       4. The stapler of claim 2 wherein said feed spring is a cantilever leaf spring and said supplementary spring has a tip which is engageable against said feed spring. 
     
     
       5. The stapler of claim 4 wherein said feed spring has a bent knee and said supplementary spring slides over said knee as said driver is advanced. 
     
     
       6. An elongated molding for assembly into a stapler, said molding comprising, a body section at one end,   a trigger section presenting a trigger at an opposite end, and   a handle section between and interconnecting the body and trigger sections,   said trigger presenting a body aperture sufficiently wide for the body section to be inserted into it,   the handle section including a portion which can be flexed to permit the trigger to be brought forwardly over the front end of said body section and the body section inserted into said aperture so that said trigger extends obliquely to the body section,   said handle section in use forming a pistol grip by which the stapler is held.   
     
     
       7. The molding of claim 6 formed as a single piece. 
     
     
       8. The molding of claim 6 further including means for connecting said trigger to the body section for pivotal movement toward the grip. 
     
     
       9. The molding of claim 8 wherein said connecting means comprises stub axle means projecting from said trigger, said axle means being receivable in co-acting holes in said body section. 
     
     
       10. The molding of claim 9 further wherein said stub axle means includes snap-in means for preventing the axle means from being withdrawn from said holes. 
     
     
       11. The molding of claim 10 wherein said body aperture is presented between said sides. 
     
     
       12. The molding of claim 6 wherein said trigger includes two sides connected by a transverse web, said sides and web forming said trigger. 
     
     
       13. The molding of claim 6 further including a staple driver, said body section including a driver guide channel into which said driver can be inserted as the body section is being inserted into said body aperture,   said channel positioning the driver for longitudinal movement in the body section.   
     
     
       14. The molding of claim 13 wherein said driver is formed between sides of said trigger. 
     
     
       15. The molding of claim 14 further wherein the trigger section includes driver advancing means connecting said trigger to said driver for advancing said driver in said channel when said trigger is pulled. 
     
     
       16. The molding of claim 13 further wherein said trigger includes pivot means connectable to the body so that the trigger can be pivoted toward the grip, said trigger having a top part which in use is above said pivot means and which moves forwardly as the trigger is pulled toward the grip, and   driver advancing means comprising at least one strap connected between said top part of the trigger, and said driver.   
     
     
       17. The molding of claim 13 including a driver retract spring comprising a spring portion between the grip and the driver, said spring portion being stressed in use as said trigger is pulled, so that it exerts a retracting force on said driver.   
     
     
       18. The molding of claim 17 wherein said spring portion extends between said grip and what in use is the rear end of said driver. 
     
     
       19. The molding of claim 18 wherein said spring portion has a S-shape. 
     
     
       20. The molding of claim 6 wherein said handle section includes a front part and a rear part and latch means for securing said parts together. 
     
     
       21. The molding of claim 6 wherein the body section includes a staple supply and a staple feed spring for urging said supply toward a staple guide passage in said body section. 
     
     
       22. The molding of claim 21 further including an anvil on said body section at a front end of said guide passage, said anvil having a depth approximating the thickness of a staple.   
     
     
       23. The molding of claim 22 further including a staple ejection spring in said body section for ejecting a staple from said anvil after closing. 
     
     
       24. The molding of claim 23 wherein said staple ejection spring is a leaf spring which projects from said body section into said staple guide passage. 
     
     
       25. The molding of claim 21 wherein said feed spring is a leaf spring projecting forwardly in said body section. 
     
     
       26. The molding of claim 21 further including a staple driver and a backup spring which extends from said driver and which in use is brought into assisting relation with said feed spring as said driver is moved to engage a staple in said guide passage. 
     
     
       27. The molding of claim 26 wherein said feed spring is formed with a bent knee, and said backup spring is shaped to slide over said knee in use. 
     
     
       28. The molding of claim 21 wherein said staple supply is located below said guide passage to feed staples into it at substantially a right angle thereto. 
     
     
       29. The molding of claim 6 further including ratchet means for preventing said driver from being withdrawn from a staple once the driver has engaged that staple. 
     
     
       30. The molding of claim 29 further wherein said trigger section includes a driver moved by the trigger in the assembled stapler, and said ratchet means includes a rack and a pawl, said rack being mounted to and moving with said driver.   
     
     
       31. The molding of claim 30 wherein the pawl is mounted from said body section by a spring, the rack being disengaged from the pawl until said stapler is used for the first time.   
     
     
       32. The molding of claim 30 further including a stop between said rack and said pawl so positioned that in use it limits movement of said rack away from said pawl. 
     
     
       33. An elongated molding for assembly into a stapler, said molding comprising, a body section at one end,   a trigger section presenting a trigger at an opposite end, and   a handle section between and interconnecting the body and trigger section,   a handle section adapted to form a pistol grip by bending back on itself, and   integral means for pivotally mounting the trigger angularly to the body section, in front of the grip.   
     
     
       34. The molding of claim 33 wherein the handle section includes a front part, a rear part, and a flexible butt part connecting the front and rear parts, whereby said rear part can be swung generally parallel to the front part to form said pistol grip. 
     
     
       35. The molding of claim 34 wherein said trigger section extends from the rear part of said handle section. 
     
     
       36. The molding of claim 35 wherein a driver is formed in said trigger section, between spaced sides of said trigger. 
     
     
       37. The molding of claim 36 wherein said trigger section includes straps which connect said trigger to the rear part of said handle section. 
     
     
       38. The molding of claim 37 further including a retract spring between the trigger and the grip, and wherein said driver is aligned with and extends from said retract spring. 
     
     
       39. The molding of claim 34 wherein said retract spring forms an S-shape upon assembly of said molding. 
     
     
       40. A stapler comprising, a body, a trigger pivotally connected to said body, and a pistol grip,   said trigger being pivoted to said body and swingable rearwardly about its pivot, toward said grip,   a driver slidable in said body in a driver guide channel therein,   said trigger including a top part which rotates forwardly when said trigger is pivoted toward said grip, and   strap means connected between said top part of said trigger and said driver, to pull the driver in said guide channel as said trigger is pulled.   
     
     
       41. The stapler of claim 40 further including ratchet means for preventing said driver from being withdrawn from a staple once the driver has engaged the staple, said ratchet means including a rack and a pawl, said rack being mounted to and moving with said driver, said pawl being mounted to said body.   
     
     
       42. The stapler of claim 41 wherein said pawl is mounted on a spring arm from said body. 
     
     
       43. The stapler of claim 42 further including a stop on said driver between said rack and said pawl which limits movement of said rack away from said pawl. 
     
     
       44. The stapler of claim 40 further wherein said body extends through a body aperture in said trigger. 
     
     
       45. The stapler of claim 40 wherein said trigger includes two sides connected by a transverse web, said body aperture is presented between said sides, and said body extends through said aperture in said trigger. 
     
     
       46. The stapler of claim 45 wherein said trigger is connected to said body by stub axle means projecting from said trigger, said axle means being received in co-acting holes in said body. 
     
     
       47. The stapler of claim 46 further wherein said stub axle means includes snap acting means for preventing the axle means from being withdrawn from said holes. 
     
     
       48. The stapler of claim 40 wherein said driver is formed integrally with said trigger and is connected to it by said strap means. 
     
     
       49. The stapler of claim 40 including an S-shaped driver retract spring connected between said driver and said grip. 
     
     
       50. The stapler of claim 49 wherein said driver retract spring is a strip of flexible plastic, and is integral with both said driver and said grip. 
     
     
       51. The stapler of claim 40 further including a staple supply and a staple feed spring for urging said supply toward a staple guide passage, said feed spring being a leaf spring, and a backup spring extending from said driver and which is brought into assisting relation with said feed spring as said driver is moved to engage a staple in said guide passage.   
     
     
       52. The stapler of claim 51 wherein said feed spring is formed with a bent knee, and said backup spring engages said feed spring between said knee and said driver. 
     
     
       53. The stapler of claim 52 wherein said backup spring is unstressed until said trigger is pulled to engage a staple. 
     
     
       54. The stapler of claim 53 wherein said backup spring exerts increasing force on said feed spring as a staple is being formed.